• Title/Summary/Keyword: negative polar

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A Review of Measures against Environmental Impact of Suspended Sediments Generated by Coastal Development Works (연안개발공사로 인한 부유토사의 환경 악영향 저감방안 고찰)

  • Song, Won-Oh;Jin, Jae-Youll;Chae, Jang-Won;Ahn, Hee-Do;Maeng, Jun-Ho;Oh, Jae-Kyung
    • Ocean and Polar Research
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    • v.25 no.spc3
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    • pp.409-416
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    • 2003
  • Coastal development works generally increase the suspended sediment concentration of the ambient water, causing environmental impacts in various manners. The most active measures in three sides have been reviewed for their applicabilities in Korea. Referring to the cases in the USA, the legislation of environmental windows seems to be not proper for Environmentally Sound and Sustainable Developments (ESSD) until sufficient scientific data are obtained to address the individual issues of potential negative impacts. Feedback monitoring can be regarded as the best way for ESSD. Korea also has the basic legal system for the feedback monitoring as well as Environmental Impact Assessments (EIA). However, the frequency, period and parameter of related surveys should be improved for the true ESSD. Moreover, environmental facilities such as environmental dredgers should be widely used for mitigating environmental Impacts caused by coastal development works.

Characterization of Immobilized Denitrifying Bacteria Isolated from Municipal Sewage

  • Kim, Joong-Kyun;Kim, Sung-Koo;Kim, Sang-Hee
    • Journal of Microbiology and Biotechnology
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    • v.11 no.5
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    • pp.756-762
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    • 2001
  • As a component for a recirculating aquaculture system, a new strain of denitrifying bacterium was isolated from municipal sewage. The isolate was motile by means of one polar flagellum, catalase-positive, and a Gram-negative rod-shaped cell measuring $0.5-0.6{\mu}m$ in width and $1.3-1.9{\mu}m$ in length. The isolate was identified as Pseudomonas fluorescens and produced dinitrogen gas via the reduction of nitrate. The optimal growth conditions (pH, temperature, carbon source, and C/N ratio) of the isolate were found to be 6.8, $30^{\circ}C$, malate, and 3, respectively. Under optimal growth conditions of P. fluorescens, dinitrogen gas was first detected in the exponential growth phase, then a small amount of nitrite was developed and converted to dinitrogen gas in the stationary phase. Pseudomonas fluorescens cells were immobilized in modified polyvinyl alcohol (PVA) gel beads, and the maximum denitrification rate was measured as $36.6 {\mu}lN_2h^-1$ per bead with an optimum cell loading of $20mg {\mu}l^-1$ and $2\%$ sodium alginate added to the PVA gel. The operating stability of the modified PVA gel beads remained unchanged for up to 43 repeated batches.

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Climate Change and Individual Life History (기후변화와 개체의 생활사)

  • Lee, Who-Seung
    • Ocean and Polar Research
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    • v.34 no.3
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    • pp.275-286
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    • 2012
  • Over the last 20 years there have been more than 3000 peer-reviewed papers relating to climate change and biodiversity published, and still the numbers are increasing. However, most studies focused on the impacts of climate change at population or community levels, and the results invariably reveal that there has been, or will be, a negative effect on the structure and pattern of biodiversity. Moreover, the climate change models and statistical analyses used to test the impacts are only newly developed, and the analyses or predictions can often be misled. In this review, I ask why an individual's life history is considered in the study how climate change affects biodiversity, and what ecological factors are impacted by climate change. Using evidence from a range of species, I demonstrate that diverse life history traits, such as early growth rate, migration/foraging behaviour and lifespan, can be shifted by climate change at individual level. Particularly I discuss that the optimal decision under unknown circumstance (climate change) would be the reduction of the ecological fitness at individual level, and hence, a shift in the balance of the ecosystem could be affected without having a critical impact on any one species. To conclude, I summarize the links between climate changes, ecological decision in life history, the revised consequence at individual level, and discuss how the finely-balanced relationship affects biodiversity and population structure.

Current Status of Bacterial Brown Stripe of Rice Caused by Acidovorax avenae subsp. avenae (Acidovorax avenae subsp. avenae에 의한 세균성줄무늬병의 연구동향)

  • 송완엽
    • Plant Disease and Agriculture
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    • v.5 no.2
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    • pp.69-76
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    • 1999
  • Acidovorax avenae subsp. avenae is the causal pathogen of several hosts including oats corn foxtail millet wheatgrass sugarcane and rice. The pathogen is a seedborne pathogen of rice and known to occur widely in rice growing countries. The pathogen cause inhibition of germination brown stripe on the leaf curling of the leaf sheath and abnormal elongation of the mesocotyl of irce. Bacterial colonies grow slowly and are convex circular and creamy with tan to brown center. The causal baterium is Gram-negative and rod shape with a single polar flagellum Nonfluorescence poly-$\beta$-hydroxybutyrate accumulation and precipitate formation around the colony on the medium are useful in the differentiation of this bacterium from other subspecies of A. avenae as well as nonfluorescent bacteria pathogenic to rice. This bacterium has belonged to the genus of Psdeudomonas but recently was transferred to the new genus Acidovorax on the basis of bacteriological and molecular biological data. However the difference of biochemical characteristics protein profile of the cell and host range among strains should be more clarified. To develop an effective control strategy for this disease understanding of detailed life cycle of the disease ritical environmental factors affecting disease development on each host and relationship to grain discoloration of rice are prerequisite. Although the affected area has been world-widely reported there is on recent progress on the understanding of the bacteriological and ecological characteristics of the causal bacterium and control means of the disease.

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Formative Properties of Sensibility and Emotion in Fashion (패션에 나타난 감성과 감정의 조형적 특성 연구)

  • 김유진;이경희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.1
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    • pp.34-44
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    • 2004
  • The purpose of this study was to provide effective design strategy and distinguish productions for the consumer's emotion satisfaction by analyzing formative properties of fashion sensibility and emotion. 54 photos of contemporary costume have been selected which represented the Izard' DES. The questionnaire consisted of bi-polar 25 pairs adjective scale of fashion sensibility and the 18 noun scale of emotion was distributed to 970 male and female living in Pusan area. The data were analyzed by GLM using the statistic SPSS package. The major findings of this research were as follows. 1. In the clothing formative properties following fashion sensibilities, aestheticism shows significant differences in the silhouette and texture, maturity in the silhouette and color, character in the texture and decoration and feminity in the pattern and color. 2. In the clothing formative properties following emotions, negative emotion shows significant differences in the pattern and silhouette, distressㆍfear in the silhouette and pattern, arousal in the texture and color, shame in the color and texture and enjoyment in the silhouette and pattern. 3. In the fashion sensibility and emotion following clothing formative properties, each formative property shows differences in fashion sensibility and emotion. This study result will be utilized in the clothing design development in special usage like theatrical costume, discriminated display and advertisement stratge.

Meiobenthic Community Structure on the Northeast Coastal Area of Jeju Island, Korea (제주 북동부 연안 조하대에 서식하는 중형저서동물 군집 변동 특성)

  • Kang, Teawook;Kim, Dongsung
    • Ocean and Polar Research
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    • v.42 no.1
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    • pp.1-13
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    • 2020
  • We analyzed the characteristics of meiofaunal communities in the northern part of Jeju Island and the environmental factors affecting the meiofaunal communities. For the analysis of the communities, subtidal sediments containing meiofauna were collected from 6 sites (3 shallow sites and 3 deeper sites) on the northern coast of Jeju Island in April, June, August, and October 2017. The sediment samples were collected by SCUBA using a syringe. After isolating and counting meiofauna from the sediment using a series of sieves and centrifugation, the density of the meiofauna was expressed as individuals/10 ㎠. Density of meiofauna was lower in August compared to April and June, and the density determined in October was higher than August. During April and June, the meiofaunal communities at the shallow sites (i.e., ST 1, 2, and 3) were significantly different from the meiofaunal communities at deeper sites (ST 4, 5, and 6, p < 0.01). However, such spatial variation in the meiofaunal communities was not obvious in August and October. The most dominant meiofaunal taxa were harpacticoids, followed by nematodes and nauplius larvae. These three taxa accounted for 90% of the total meiofauna density. Abundance of harpacticoids and nematodes showed a significantly negative correlation with the water depth. BIO-ENV analysis indicated that the total organic nitrogen (TON) and the water temperature exerted a significant influence over the meiofaunal communities at the sampling sites.

Isolation and Identification of Photosynthetic Bacterium Useful for Wastewater Treatment

  • Choi, Han-Pil;Kang, Hyun-Jun;Seo, Ho-Chan;Sung, Ha-Chin
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.643-648
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    • 2002
  • For wastewater treatment and utilization of the biomass, a photosynthetic bacterium was isolated based on its cell growth rate, cell mass, and assimilating ability of organic acids. The isolate was a Gram-negative rod-shaped bacterium that contained a single polar flagellum and formed a lamellar intracytoplasmic membrane (ICM) system, including bacteriochlorophyll $\alpha$. The major isoprenoid quinone component was identified as ubiquinone Q-10, and the fatty acid composition was characterized as to contain relatively large amount of C-16:0 (18.74%) and C-18:1 (59.23%). Based on its morphology, phototrophic properties, quinone component, and fatty acid composition, the isolate appeared to be closely related to the Rhodopseudomonas subgroup of purple nonsulfur bacteria. A phylogenetic analysis of the isolate using its 16S rRNA gene sequence data also supported the phenotypic findings, and classified the isolate closely related to Rhodopseudomonas palustris. Accordingly, the nomenclature of the isolate was proposed as Rhodopseudomonas palustris KUGB306. A bench-scale photosynthetic bacteria (PSB) reactor using the isolate was designed and operated for the treatment of soybean curd wastewater.

Chitinimonas naiadis sp. nov., Isolated from a Freshwater River

  • Padakandla, Shalem Raj;Chae, Jong-Chan
    • Journal of Microbiology and Biotechnology
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    • v.27 no.7
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    • pp.1300-1305
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    • 2017
  • A rod shaped, aerobic, Gram-stain-negative, and motile bacterium, strain $AR2^T$, was isolated from a water sample of Yeongsan river, Republic of Korea. Strain $AR2^T$ clustered closely with the members of the genus Chitinimonas and showed the highest 16S rRNA gene sequence similarity with Chitinimonas prasina $LY03^T$ (96.4%), Chitinimonas viridis $HMD2169^T$ (96.4%), Chitinimonas taiwanensis $cf^T$ (96.2%), and Chitinimonas koreensis $R2A43-10^T$ (94.2%). The predominant fatty acids of strain $AR2^T$ were identified to be summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$), $C_{16:0}$, and $C_{10:0}3-OH$. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were found to be the major polar lipids. The genomic DNA G+C content was 60.4 mol%. Based on the polyphasic characterization, the isolated strain $AR2^T$ is described as a representative of a novel species in the genus Chitinimonas, for which the name Chitinimonas naiadis sp. nov. (type strain =$AR2^T$ =KCTC $42755^T$ =JCM $31504^T$) is proposed.

Reaction Dynamics of CH3 + HBr → CH4 + Br at 150-1000 K

  • Ree, Jongbaik;Kim, Yoo Hang;Shin, Hyung Kyu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.8
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    • pp.2473-2479
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    • 2013
  • The kinetics of the radical-polar molecule reaction $CH_3+HBr{\rightarrow}CH_4+Br$ has been studied at temperatures between 150 and 1000 K using classical dynamics procedures. Potential energy surfaces constructed using analytical forms of inter- and intramolecular interaction energies show a shallow well and barrier in the entrance channel, which affect the collision dynamics at low temperatures. Different collision models are used to distinguish the reaction occurring at low- and high-temperature regions. The reaction proceeds rapidly via a complex-mode mechanism below room temperature showing strong negative temperature dependence, where the effects of molecular attraction, H-atom tunneling and recrossing of collision complexes are found to be important. The temperature dependence of the rate constant between 400 and 1000 K is positive, the values increasing in accordance with the increase of the mean speed of collision. The rate constant varies from $7.6{\times}10^{-12}$ at 150 K to $3.7{\times}10^{-12}$ at 1000 K via a minimum value of $2.5{\times}10^{-12}\;cm^3\;molecule^{-1}\;s^{-1}$ at 400 K.

Aureivirga callyspongiae sp. nov., Isolated from Marine Sponge Callyspongia elegans

  • Park, So Hyun;Kim, Ji Young;Heo, Moon Soo
    • Microbiology and Biotechnology Letters
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    • v.49 no.3
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    • pp.384-390
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    • 2021
  • A Gram-negative, aerobic, motile by gliding, and rod-shaped marine bacterium, designated CE67T was isolated from the marine sponge Callyspongia elegans on Biyang-do in Jeju Island. The CE67T strain grew optimally at 25℃, pH 7.5, and in the presence of 2-3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain CE67T was related to the genus Aureivirga and had the highest 16S rRNA gene sequence similarity to the Aureivirga marina VIII.04T type strain (96.3%). The primary fatty acids (>10%) of strain CE67T were iso-C15:0 (35.3%) and iso-C17:0 3OH (21.8%). The polar lipid profile of strain CE67T contained phosphatidylethanolamine, unidentified aminolipids, and unidentified lipids. The predominant menaquinone was MK-6. The DNA G+C content was 29.1 mol%. Based on the polyphasic taxonomic analysis, strain CE67T was determined to be a representative novel species of the genus Aureivirga for which we propose the name Aureivirga callyspongiae sp. nov., whose strain type is CE67T (=KCTC 42847T=JCM 34566T).